1 /*
2 * Copyright (c) 2003-2021 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /*
30 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Neither the name of the project nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58 /*
59 * Copyright 1994, 1995 Massachusetts Institute of Technology
60 *
61 * Permission to use, copy, modify, and distribute this software and
62 * its documentation for any purpose and without fee is hereby
63 * granted, provided that both the above copyright notice and this
64 * permission notice appear in all copies, that both the above
65 * copyright notice and this permission notice appear in all
66 * supporting documentation, and that the name of M.I.T. not be used
67 * in advertising or publicity pertaining to distribution of the
68 * software without specific, written prior permission. M.I.T. makes
69 * no representations about the suitability of this software for any
70 * purpose. It is provided "as is" without express or implied
71 * warranty.
72 *
73 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
74 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
75 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
76 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
77 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
78 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
79 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
80 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
81 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
82 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
83 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
84 * SUCH DAMAGE.
85 *
86 */
87
88 /*
89 * This code does two things necessary for the enhanced TCP metrics to
90 * function in a useful manner:
91 * 1) It marks all non-host routes as `cloning', thus ensuring that
92 * every actual reference to such a route actually gets turned
93 * into a reference to a host route to the specific destination
94 * requested.
95 * 2) When such routes lose all their references, it arranges for them
96 * to be deleted in some random collection of circumstances, so that
97 * a large quantity of stale routing data is not kept in kernel memory
98 * indefinitely. See in6_rtqtimo() below for the exact mechanism.
99 */
100
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/kernel.h>
104 #include <sys/sysctl.h>
105 #include <kern/queue.h>
106 #include <sys/socket.h>
107 #include <sys/socketvar.h>
108 #include <sys/protosw.h>
109 #include <sys/mbuf.h>
110 #include <sys/syslog.h>
111 #include <sys/mcache.h>
112 #include <kern/locks.h>
113
114 #include <net/if.h>
115 #include <net/route.h>
116 #include <netinet/in.h>
117 #include <netinet/ip_var.h>
118 #include <netinet/in_var.h>
119
120 #include <netinet/ip6.h>
121 #include <netinet6/ip6_var.h>
122
123 #include <netinet/icmp6.h>
124
125 #include <netinet/tcp.h>
126 #include <netinet/tcp_seq.h>
127 #include <netinet/tcp_timer.h>
128 #include <netinet/tcp_var.h>
129
130 extern int tvtohz(struct timeval *);
131
132 static int in6_rtqtimo_run; /* in6_rtqtimo is scheduled to run */
133 static void in6_rtqtimo(void *);
134 static void in6_sched_rtqtimo(struct timeval *);
135
136 static struct radix_node *in6_addroute(void *, void *, struct radix_node_head *,
137 struct radix_node *);
138 static struct radix_node *in6_deleteroute(void *, void *,
139 struct radix_node_head *);
140 static struct radix_node *in6_matroute(void *, struct radix_node_head *);
141 static struct radix_node *in6_matroute_args(void *, struct radix_node_head *,
142 rn_matchf_t *, void *);
143 static void in6_clsroute(struct radix_node *, struct radix_node_head *);
144 static int in6_rtqkill(struct radix_node *, void *);
145
146 /*
147 * Accessed by in6_addroute(), in6_deleteroute() and in6_rtqkill(), during
148 * which the routing lock (rnh_lock) is held and thus protects the variable.
149 */
150 static int in6dynroutes;
151
152 /*
153 * Do what we need to do when inserting a route.
154 */
155 static struct radix_node *
in6_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node * treenodes)156 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
157 struct radix_node *treenodes)
158 {
159 struct rtentry *rt = (struct rtentry *)treenodes;
160 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)(void *)rt_key(rt);
161 struct radix_node *ret;
162 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
163 uint32_t flags = rt->rt_flags;
164 boolean_t verbose = (rt_verbose > 1);
165
166 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
167 RT_LOCK_ASSERT_HELD(rt);
168
169 if (verbose) {
170 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
171 }
172
173 /*
174 * If this is a dynamic route (which is created via Redirect) and
175 * we already have the maximum acceptable number of such route entries,
176 * reject creating a new one. We could initiate garbage collection to
177 * make available space right now, but the benefit would probably not
178 * be worth the cleaning overhead; we only have to endure a slightly
179 * suboptimal path even without the redirected route.
180 */
181 if ((rt->rt_flags & RTF_DYNAMIC) &&
182 ip6_maxdynroutes >= 0 && in6dynroutes >= ip6_maxdynroutes) {
183 return NULL;
184 }
185
186 /*
187 * For IPv6, all unicast non-host routes are automatically cloning.
188 */
189 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
190 rt->rt_flags |= RTF_MULTICAST;
191 }
192
193 if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {
194 rt->rt_flags |= RTF_PRCLONING;
195 }
196
197 /*
198 * A little bit of help for both IPv6 output and input:
199 * For local addresses, we make sure that RTF_LOCAL is set,
200 * with the thought that this might one day be used to speed up
201 * ip_input().
202 *
203 * We also mark routes to multicast addresses as such, because
204 * it's easy to do and might be useful (but this is much more
205 * dubious since it's so easy to inspect the address). (This
206 * is done above.)
207 *
208 * XXX
209 * should elaborate the code.
210 */
211 if (rt->rt_flags & RTF_HOST) {
212 IFA_LOCK_SPIN(rt->rt_ifa);
213 if (in6_are_addr_equal_scoped(&satosin6(rt->rt_ifa->ifa_addr)->
214 sin6_addr, &sin6->sin6_addr, satosin6(rt->rt_ifa->ifa_addr)->sin6_scope_id, sin6->sin6_scope_id)) {
215 rt->rt_flags |= RTF_LOCAL;
216 }
217 IFA_UNLOCK(rt->rt_ifa);
218 }
219
220 if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
221 rt->rt_ifp) {
222 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
223 }
224
225 /*
226 * rn_addroute route returns NULL if an exact entry is being attempted
227 * to be added again.
228 */
229 ret = rn_addroute(v_arg, n_arg, head, treenodes);
230 if (ret == NULL && (rt->rt_flags & RTF_HOST)) {
231 struct rtentry *rt2;
232 /*
233 * We are trying to add a host route, but can't.
234 * Find out if it is because of an
235 * ND6 entry and delete it if so.
236 */
237 rt2 = rtalloc1_scoped_locked((struct sockaddr *)sin6, 0,
238 RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
239 if (rt2 != NULL) {
240 char dbufc[MAX_IPv6_STR_LEN];
241
242 RT_LOCK(rt2);
243 if (verbose) {
244 rt_str(rt2, dbufc, sizeof(dbufc), NULL, 0);
245 }
246
247 if ((rt2->rt_flags & RTF_LLINFO) &&
248 (rt2->rt_flags & RTF_HOST) &&
249 rt2->rt_gateway != NULL &&
250 rt2->rt_gateway->sa_family == AF_LINK) {
251 if (verbose) {
252 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert "
253 "route to %s:%s, flags=%b, due to "
254 "existing ND6 route %s->%s "
255 "flags=%b, attempting to delete\n",
256 __func__, dbuf,
257 (rt->rt_ifp != NULL) ?
258 rt->rt_ifp->if_xname : "",
259 rt->rt_flags, RTF_BITS,
260 dbufc, (rt2->rt_ifp != NULL) ?
261 rt2->rt_ifp->if_xname : "",
262 rt2->rt_flags, RTF_BITS);
263 }
264 /*
265 * Safe to drop rt_lock and use rt_key,
266 * rt_gateway, since holding rnh_lock here
267 * prevents another thread from calling
268 * rt_setgate() on this route.
269 */
270 RT_UNLOCK(rt2);
271 (void) rtrequest_locked(RTM_DELETE, rt_key(rt2),
272 rt2->rt_gateway, rt_mask(rt2),
273 rt2->rt_flags, NULL);
274 ret = rn_addroute(v_arg, n_arg, head,
275 treenodes);
276 } else {
277 RT_UNLOCK(rt2);
278 }
279 rtfree_locked(rt2);
280 }
281 } else if (ret == NULL && (rt->rt_flags & RTF_CLONING)) {
282 struct rtentry *rt2;
283 /*
284 * We are trying to add a net route, but can't.
285 * The following case should be allowed, so we'll make a
286 * special check for this:
287 * Two IPv6 addresses with the same prefix is assigned
288 * to a single interrface.
289 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
290 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
291 * In this case, (*1) and (*2) want to add the same
292 * net route entry, 3ffe:0501:: -> if0.
293 * This case should not raise an error.
294 */
295 rt2 = rtalloc1_scoped_locked((struct sockaddr *)sin6, 0,
296 RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
297 if (rt2 != NULL) {
298 RT_LOCK(rt2);
299 if ((rt2->rt_flags & (RTF_CLONING | RTF_HOST |
300 RTF_GATEWAY)) == RTF_CLONING &&
301 rt2->rt_gateway &&
302 rt2->rt_gateway->sa_family == AF_LINK &&
303 rt2->rt_ifp == rt->rt_ifp) {
304 ret = rt2->rt_nodes;
305 }
306 RT_UNLOCK(rt2);
307 rtfree_locked(rt2);
308 }
309 }
310
311 if (ret != NULL && (rt->rt_flags & RTF_DYNAMIC)) {
312 in6dynroutes++;
313 }
314
315 if (!verbose) {
316 goto done;
317 }
318
319 if (ret != NULL) {
320 if (flags != rt->rt_flags) {
321 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
322 "oflags=%b, flags=%b\n", __func__,
323 dbuf, gbuf, (rt->rt_ifp != NULL) ?
324 rt->rt_ifp->if_xname : "", flags, RTF_BITS,
325 rt->rt_flags, RTF_BITS);
326 } else {
327 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
328 "flags=%b\n", __func__, dbuf, gbuf,
329 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
330 rt->rt_flags, RTF_BITS);
331 }
332 } else {
333 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert route to %s->%s->%s, "
334 "flags=%b, already exists\n", __func__, dbuf, gbuf,
335 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
336 rt->rt_flags, RTF_BITS);
337 }
338 done:
339 return ret;
340 }
341
342 static struct radix_node *
in6_deleteroute(void * v_arg,void * netmask_arg,struct radix_node_head * head)343 in6_deleteroute(void *v_arg, void *netmask_arg, struct radix_node_head *head)
344 {
345 struct radix_node *rn;
346
347 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
348
349 rn = rn_delete(v_arg, netmask_arg, head);
350 if (rn != NULL) {
351 struct rtentry *rt = (struct rtentry *)rn;
352
353 RT_LOCK(rt);
354 if (rt->rt_flags & RTF_DYNAMIC) {
355 in6dynroutes--;
356 }
357 if (rt_verbose > 1) {
358 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
359
360 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
361 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s deleted, "
362 "flags=%b\n", __func__, dbuf, gbuf,
363 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
364 rt->rt_flags, RTF_BITS);
365 }
366 RT_UNLOCK(rt);
367 }
368 return rn;
369 }
370
371 /*
372 * Validate (unexpire) an expiring AF_INET6 route.
373 */
374 struct radix_node *
in6_validate(struct radix_node * rn)375 in6_validate(struct radix_node *rn)
376 {
377 struct rtentry *rt = (struct rtentry *)rn;
378
379 RT_LOCK_ASSERT_HELD(rt);
380
381 /* This is first reference? */
382 if (rt->rt_refcnt == 0) {
383 if (rt_verbose > 2) {
384 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
385
386 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
387 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s validated, "
388 "flags=%b\n", __func__, dbuf, gbuf,
389 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
390 rt->rt_flags, RTF_BITS);
391 }
392
393 /*
394 * It's one of ours; unexpire it. If the timer is already
395 * scheduled, let it run later as it won't re-arm itself
396 * if there's nothing to do.
397 */
398 if (rt->rt_flags & RTPRF_OURS) {
399 rt->rt_flags &= ~RTPRF_OURS;
400 rt_setexpire(rt, 0);
401 }
402 }
403 return rn;
404 }
405
406 /*
407 * Similar to in6_matroute_args except without the leaf-matching parameters.
408 */
409 static struct radix_node *
in6_matroute(void * v_arg,struct radix_node_head * head)410 in6_matroute(void *v_arg, struct radix_node_head *head)
411 {
412 return in6_matroute_args(v_arg, head, NULL, NULL);
413 }
414
415 /*
416 * This code is the inverse of in6_clsroute: on first reference, if we
417 * were managing the route, stop doing so and set the expiration timer
418 * back off again.
419 */
420 static struct radix_node *
in6_matroute_args(void * v_arg,struct radix_node_head * head,rn_matchf_t * f,void * w)421 in6_matroute_args(void *v_arg, struct radix_node_head *head,
422 rn_matchf_t *f, void *w)
423 {
424 struct radix_node *rn = rn_match_args(v_arg, head, f, w);
425
426 if (rn != NULL) {
427 RT_LOCK_SPIN((struct rtentry *)rn);
428 in6_validate(rn);
429 RT_UNLOCK((struct rtentry *)rn);
430 }
431 return rn;
432 }
433
434 SYSCTL_DECL(_net_inet6_ip6);
435
436 /* one hour is ``really old'' */
437 static uint32_t rtq_reallyold = 60 * 60;
438 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
439 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_reallyold, 0, "");
440
441 /* never automatically crank down to less */
442 static uint32_t rtq_minreallyold = 10;
443 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
444 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_minreallyold, 0, "");
445
446 /* 128 cached routes is ``too many'' */
447 static uint32_t rtq_toomany = 128;
448 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
449 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_toomany, 0, "");
450
451 /*
452 * On last reference drop, mark the route as belong to us so that it can be
453 * timed out.
454 */
455 static void
in6_clsroute(struct radix_node * rn,struct radix_node_head * head)456 in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
457 {
458 #pragma unused(head)
459 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
460 struct rtentry *rt = (struct rtentry *)rn;
461 boolean_t verbose = (rt_verbose > 1);
462
463 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
464 RT_LOCK_ASSERT_HELD(rt);
465
466 if (!(rt->rt_flags & RTF_UP)) {
467 return; /* prophylactic measures */
468 }
469 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) {
470 return;
471 }
472
473 if (rt->rt_flags & RTPRF_OURS) {
474 return;
475 }
476
477 if (!(rt->rt_flags & (RTF_WASCLONED | RTF_DYNAMIC))) {
478 return;
479 }
480
481 if (verbose) {
482 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
483 }
484
485 /*
486 * Delete the route immediately if RTF_DELCLONE is set or
487 * if route caching is disabled (rtq_reallyold set to 0).
488 * Otherwise, let it expire and be deleted by in6_rtqkill().
489 */
490 if ((rt->rt_flags & RTF_DELCLONE) || rtq_reallyold == 0) {
491 int err;
492
493 if (verbose) {
494 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to %s->%s->%s, "
495 "flags=%b\n", __func__, dbuf, gbuf,
496 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
497 rt->rt_flags, RTF_BITS);
498 }
499 /*
500 * Delete the route from the radix tree but since we are
501 * called when the route's reference count is 0, don't
502 * deallocate it until we return from this routine by
503 * telling rtrequest that we're interested in it.
504 * Safe to drop rt_lock and use rt_key, rt_gateway,
505 * since holding rnh_lock here prevents another thread
506 * from calling rt_setgate() on this route.
507 */
508 RT_UNLOCK(rt);
509 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
510 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &rt);
511 if (err == 0) {
512 /* Now let the caller free it */
513 RT_LOCK(rt);
514 RT_REMREF_LOCKED(rt);
515 } else {
516 RT_LOCK(rt);
517 if (!verbose) {
518 rt_str(rt, dbuf, sizeof(dbuf),
519 gbuf, sizeof(gbuf));
520 }
521 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
522 "%s->%s->%s, flags=%b, err=%d\n", __func__,
523 dbuf, gbuf, (rt->rt_ifp != NULL) ?
524 rt->rt_ifp->if_xname : "", rt->rt_flags,
525 RTF_BITS, err);
526 }
527 } else {
528 uint64_t timenow;
529
530 timenow = net_uptime();
531 rt->rt_flags |= RTPRF_OURS;
532 rt_setexpire(rt, timenow + rtq_reallyold);
533
534 if (verbose) {
535 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s invalidated, "
536 "flags=%b, expire=T+%u\n", __func__, dbuf, gbuf,
537 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
538 rt->rt_flags, RTF_BITS, rt->rt_expire - timenow);
539 }
540
541 /* We have at least one entry; arm the timer if not already */
542 in6_sched_rtqtimo(NULL);
543 }
544 }
545
546 struct rtqk_arg {
547 struct radix_node_head *rnh;
548 int updating;
549 int draining;
550 uint32_t killed;
551 uint32_t found;
552 uint64_t nextstop;
553 };
554
555 /*
556 * Get rid of old routes. When draining, this deletes everything, even when
557 * the timeout is not expired yet. This also applies if the route is dynamic
558 * and there are sufficiently large number of such routes (more than a half of
559 * maximum). When updating, this makes sure that nothing has a timeout longer
560 * than the current value of rtq_reallyold.
561 */
562 static int
in6_rtqkill(struct radix_node * rn,void * rock)563 in6_rtqkill(struct radix_node *rn, void *rock)
564 {
565 struct rtqk_arg *ap = rock;
566 struct rtentry *rt = (struct rtentry *)rn;
567 boolean_t verbose = (rt_verbose > 1);
568 uint64_t timenow;
569 int err;
570
571 timenow = net_uptime();
572 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
573
574 RT_LOCK(rt);
575 if (rt->rt_flags & RTPRF_OURS) {
576 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
577
578 if (verbose) {
579 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
580 }
581
582 ap->found++;
583 VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0);
584 VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0);
585 if (ap->draining || rt->rt_expire <= timenow ||
586 ((rt->rt_flags & RTF_DYNAMIC) && ip6_maxdynroutes >= 0 &&
587 in6dynroutes > ip6_maxdynroutes / 2)) {
588 if (rt->rt_refcnt > 0) {
589 panic("%s: route %p marked with RTPRF_OURS "
590 "with non-zero refcnt (%u)", __func__,
591 rt, rt->rt_refcnt);
592 /* NOTREACHED */
593 }
594
595 if (verbose) {
596 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to "
597 "%s->%s->%s, flags=%b, draining=%d\n",
598 __func__, dbuf, gbuf, (rt->rt_ifp != NULL) ?
599 rt->rt_ifp->if_xname : "", rt->rt_flags,
600 RTF_BITS, ap->draining);
601 }
602 RT_ADDREF_LOCKED(rt); /* for us to free below */
603 /*
604 * Delete this route since we're done with it;
605 * the route may be freed afterwards, so we
606 * can no longer refer to 'rt' upon returning
607 * from rtrequest(). Safe to drop rt_lock and
608 * use rt_key, rt_gateway, since holding rnh_lock
609 * here prevents another thread from calling
610 * rt_setgate() on this route.
611 */
612 RT_UNLOCK(rt);
613 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
614 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
615 if (err != 0) {
616 RT_LOCK(rt);
617 if (!verbose) {
618 rt_str(rt, dbuf, sizeof(dbuf),
619 gbuf, sizeof(gbuf));
620 }
621 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
622 "%s->%s->%s, flags=%b, err=%d\n", __func__,
623 dbuf, gbuf, (rt->rt_ifp != NULL) ?
624 rt->rt_ifp->if_xname : "", rt->rt_flags,
625 RTF_BITS, err);
626 RT_UNLOCK(rt);
627 } else {
628 ap->killed++;
629 }
630 rtfree_locked(rt);
631 } else {
632 uint64_t expire = (rt->rt_expire - timenow);
633
634 if (ap->updating && expire > rtq_reallyold) {
635 rt_setexpire(rt, timenow + rtq_reallyold);
636 if (verbose) {
637 os_log_debug(OS_LOG_DEFAULT, "%s: route to "
638 "%s->%s->%s, flags=%b, adjusted "
639 "expire=T+%u (was T+%u)\n",
640 __func__, dbuf, gbuf,
641 (rt->rt_ifp != NULL) ?
642 rt->rt_ifp->if_xname : "",
643 rt->rt_flags, RTF_BITS,
644 (rt->rt_expire - timenow), expire);
645 }
646 }
647 ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
648 RT_UNLOCK(rt);
649 }
650 } else {
651 RT_UNLOCK(rt);
652 }
653
654 return 0;
655 }
656
657 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
658 static int rtq_timeout = RTQ_TIMEOUT;
659
660 static void
in6_rtqtimo(void * targ)661 in6_rtqtimo(void *targ)
662 {
663 #pragma unused(targ)
664 struct radix_node_head *rnh;
665 struct rtqk_arg arg;
666 struct timeval atv;
667 static uint64_t last_adjusted_timeout = 0;
668 boolean_t verbose = (rt_verbose > 1);
669 uint64_t timenow;
670 uint32_t ours;
671
672 lck_mtx_lock(rnh_lock);
673 rnh = rt_tables[AF_INET6];
674 VERIFY(rnh != NULL);
675
676 /* Get the timestamp after we acquire the lock for better accuracy */
677 timenow = net_uptime();
678 if (verbose) {
679 os_log_debug(OS_LOG_DEFAULT, "%s: initial nextstop is T+%u seconds\n",
680 __func__, rtq_timeout);
681 }
682 bzero(&arg, sizeof(arg));
683 arg.rnh = rnh;
684 arg.nextstop = timenow + rtq_timeout;
685 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
686 if (verbose) {
687 os_log_debug(OS_LOG_DEFAULT, "%s: found %u, killed %u\n", __func__,
688 arg.found, arg.killed);
689 }
690 /*
691 * Attempt to be somewhat dynamic about this:
692 * If there are ``too many'' routes sitting around taking up space,
693 * then crank down the timeout, and see if we can't make some more
694 * go away. However, we make sure that we will never adjust more
695 * than once in rtq_timeout seconds, to keep from cranking down too
696 * hard.
697 */
698 ours = (arg.found - arg.killed);
699 if (ours > rtq_toomany &&
700 ((timenow - last_adjusted_timeout) >= (uint64_t)rtq_timeout) &&
701 rtq_reallyold > rtq_minreallyold) {
702 rtq_reallyold = 2 * rtq_reallyold / 3;
703 if (rtq_reallyold < rtq_minreallyold) {
704 rtq_reallyold = rtq_minreallyold;
705 }
706
707 last_adjusted_timeout = timenow;
708 if (verbose) {
709 os_log_debug(OS_LOG_DEFAULT, "%s: adjusted rtq_reallyold to %d "
710 "seconds\n", __func__, rtq_reallyold);
711 }
712 arg.found = arg.killed = 0;
713 arg.updating = 1;
714 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
715 }
716
717 atv.tv_usec = 0;
718 atv.tv_sec = arg.nextstop - timenow;
719 /* re-arm the timer only if there's work to do */
720 in6_rtqtimo_run = 0;
721 if (ours > 0) {
722 in6_sched_rtqtimo(&atv);
723 } else if (verbose) {
724 os_log_debug(OS_LOG_DEFAULT, "%s: not rescheduling timer\n", __func__);
725 }
726 lck_mtx_unlock(rnh_lock);
727 }
728
729 static void
in6_sched_rtqtimo(struct timeval * atv)730 in6_sched_rtqtimo(struct timeval *atv)
731 {
732 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
733
734 if (!in6_rtqtimo_run) {
735 struct timeval tv;
736
737 if (atv == NULL) {
738 tv.tv_usec = 0;
739 tv.tv_sec = MAX(rtq_timeout / 10, 1);
740 atv = &tv;
741 }
742 if (rt_verbose > 1) {
743 os_log_debug(OS_LOG_DEFAULT, "%s: timer scheduled in "
744 "T+%llus.%lluu\n", __func__,
745 (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec);
746 }
747 in6_rtqtimo_run = 1;
748 timeout(in6_rtqtimo, NULL, tvtohz(atv));
749 }
750 }
751
752 void
in6_rtqdrain(void)753 in6_rtqdrain(void)
754 {
755 struct radix_node_head *rnh;
756 struct rtqk_arg arg;
757
758 if (rt_verbose > 1) {
759 os_log_debug(OS_LOG_DEFAULT, "%s: draining routes\n", __func__);
760 }
761
762 lck_mtx_lock(rnh_lock);
763 rnh = rt_tables[AF_INET6];
764 VERIFY(rnh != NULL);
765 bzero(&arg, sizeof(arg));
766 arg.rnh = rnh;
767 arg.draining = 1;
768 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
769 lck_mtx_unlock(rnh_lock);
770 }
771
772 /*
773 * Initialize our routing tree.
774 */
775 int
in6_inithead(void ** head,int off)776 in6_inithead(void **head, int off)
777 {
778 struct radix_node_head *rnh;
779
780 /* If called from route_init(), make sure it is exactly once */
781 VERIFY(head != (void **)&rt_tables[AF_INET6] || *head == NULL);
782
783 if (!rn_inithead(head, off)) {
784 return 0;
785 }
786
787 /*
788 * We can get here from nfs_subs.c as well, in which case this
789 * won't be for the real routing table and thus we're done;
790 * this also takes care of the case when we're called more than
791 * once from anywhere but route_init().
792 */
793 if (head != (void **)&rt_tables[AF_INET6]) {
794 return 1; /* only do this for the real routing table */
795 }
796 rnh = *head;
797 rnh->rnh_addaddr = in6_addroute;
798 rnh->rnh_deladdr = in6_deleteroute;
799 rnh->rnh_matchaddr = in6_matroute;
800 rnh->rnh_matchaddr_args = in6_matroute_args;
801 rnh->rnh_close = in6_clsroute;
802 return 1;
803 }
804